A first-time visit to New York's Grand Central Station can be a perplexing experience. Step inside, preferably from the taxi pick-up area at the western end, and before you will soar the vaulted expanse of its concourse, surmounted by a blue-painted ceiling depicting a starlit sky.

The monumental scale alone, even in this city of of soaring office towers, will dumbfound you. But search the indicator boards for trains with romantic names to far-off cities such as Chicago and St Louis, and you will be disappointed.

At its opening in 1913, Grand Central was a temple both to railroading, which had provided the arteries for America's growth into an industrial power, and to the vigour of New York itself. It boasted vast kitchens to prepare meals for those departing on transcontinental journeys as well as Turkish baths, private changing rooms and showers. Those were the halcyon days. Today, the furthest-flung destination served by trains at the station is New Haven, Connecticut, just 90 minutes away.

For most of this century, Grand Central, and all of the once-great railway stations of the eastern United States, were allowed to slide into undignified decay and neglect that reflected the slow displacement of passenger train travel by cars and the interstate road system, and more recently by the aeroplane.

The original Penn Station, modelled after the Roman baths of Caracalla, was demolished in 1965 to make way for office buildings and the Madison Square Garden sports arena. Its modern counterpart, whence all remaining inter-city services from New York now depart, lies beneath the Garden and offers the visitor no inspiration at all. Rather, it is a cramped and threatening Hades.

The condition of America's passenger rail system, now in the hands of the semi-nationalised Amtrak, is still perilous. Penny-pinching in Washington has seen a sharp drop in federal subsidies to Amtrak, which has been forced to cut services further to stave off bankruptcy.

The great east coast stations, however, are suddenly the objects of love and care again. From Boston to Washington - with New Haven, New York, Philadelphia, Wilmington and Baltimore in between - stations are being reborn, and not just as places to catch trains from but as destinations themselves.

The standard was set with the completion eight years ago of renovations to Washington's Union Station. A gleaming palace of towering white marble, it has become one of the capital's most visited sites, in part because it has been filled with no fewer than 100 shops, seven first-class restaurants and dozens of fast-food concessions.

Most recently refurbished was Baltimore's once-gloomy 19th-century depot, which was rechristened with the "Penn Station Sensation Ball" last December. Proud Baltimorians flocked to the event to dance and witness the restarting of the station's giant clock, whose hands, as if to symbolise five decades of neglect, had been immobile since the Forties.

The impetus for these renovations may, ironically, have been provided by the razing of the old Penn Station over 30 years ago. The outcry from appalled conservationists led to a new national awareness of urban architecture and, specifically, the creation in New York of the Landmarks Preservation Commission which granted the city powers to protect buildings from the whims of developers. One of the commission's most important early acts was to repel plans to put a bowling alley in Grand Central's main waiting room and build a 50-storey office tower above it.

By resurrecting the stations - while also giving them some modern allure, with known-name shops and bistros - today's architects are also attempting to reverse the centrifugal forces of suburbanisation that gathered in the Fifties and Sixties and in which depots like Grand Central played so important a part. To draw back the suburban dweller, if only for weekend visits, cities realised that they had to rediscover some of their lost civic lustre. There seemed no better place to start than in the stations themselves.

Now New York is joining in. As any of the half million commuters who use Grand Central each day will attest, the terminus has temporarily become still more hellish than usual thanks to the start of a $100m renovation project.

When it is finished in two years, however, it should be returned to something close to its original Beaux Arts glory (though minus the Turkish baths and kitchens). False walls and ceilings that have been thrown up over the decades will be torn away, new entrances and staircases will be built and shops and restaurants will be added.

To the relief of many, the plans seek to preserve much of the original architectural integrity of the building and avoid turning it into a shopping mall that just happens to have train platforms attached to it - a criticism often heard of the Union Station development. "Grand Central is New York's living room," Susan Fine, a director of the Metropolitan Transportation Authority, said when the work began. "New Yorkers deserve a better living room than the one they have now."

Much more radical, however, are the plans for Penn Station. The much- lamented original structure, with an exterior facade on Eighth Avenue of tall Tuscan pillars, was designed by the architectural firm of McKim, Mead and White. Opposite the site, still stands the main New York Post Office, built by the same firm in a not dissimilar classical design.

After several years of struggle, the $300m funds are almost in place to begin work on the obvious: moving Penn Station from the catacombs beneath Madison Square Garden into the Post Office building.

The front half of the building will be transformed into a station in the old, classic style, though again with modern retail additions. Accessing the tracks will be no problem: they already run directly beneath the Post Office on their way to the existing station across Seventh Avenue.

The cliche runs that America's railway stations are its cathedrals. If so, then the people lost their religion somewhere around the middle of this century. Now, the cathedrals, at least, are being returned to their original splendour, but whether that means a return also of the old devotion to travel by rail is another thing.